Base Parametric Design for the Frame Centre

Ok I’ve started modeling the CAD file for the main centre of the frame, which will contain the electronics and hold the arms in place.

The first step is to create a base sketch that maintains the shape that I want. One thing I do want to ensure is that the motors are all equidistant; that they form a square. This, while not strictly necessary, means that the quad will react in the exact same way in both directions.

Because I’d rather have a longer and thinner frame than a big fat one, I’ve decided to have a rectangular space for the components in the middle and have a separate space on each end for the attachment of the arms:

A quick sketch of what I mean
A quick sketch of what I mean

In the CAD software (Autodesk Fusion 360, which is essentially the same as Inventor but cloud-based), I have opted to make extensive use of ‘parameters’, akin to variables/constants in code: I can set dimensions to ‘centre_width’ or ‘fitting_depth’ etc.
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Gravimetric Corrections for the IMU

Although I’m still not entirely happy with my solution for the sensor fusion, I need to move on and if it creates a problem later on I’ll come back to it.

Just a note on the sensor fusion: I’ve discovered that it actually seems quite complicated to work out change in altitude from change in air pressure, and because I don’t really need this unless I have altitude hold, which I’m not going to implement for now, I’ve dropped any mention of pressure, temperature or altitude and am not using the barometer on board (for now at least).

This opens up possibilities of an open casing (or transparent) as the barometer is, as far as I know, the only light/wind-sensitive component, however I still plan to stick to a closed casing for the time being.
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